The proposed research demonstrates the feasibility for two innovative evaluation procedures for diagnostic screening and treatment outcome assessment for sleep apnea (SA). The Alertness for diagnostic screening and treatment outcome assessment for sleep apnea (SA). The Alertness Profiler (AP) combines an easy-to-apply electroencephalographic (EEG) monitoring system and PC-based vigilance, attention and memory tests in a 90-minute protocol designed to quantify levels of daytime drowsiness and their effects on performance. The AP will be evaluated with 20 SA patients and 20 health subjects and referenced to a previously collected normative database. The Apnea Risk Evaluation System (ARES) is an integrated system including: a physiological data acquisition device for monitoring SpO2, pulse, snoring and head position, easily self-applied and comfortably worn overnight to screen for SA; software to identify respiratory events and artifacts; a validated questionnaire to assess risk factors commonly associated with SA; and an expert system to classify individuals into five risk levels for SA. During Phase I, the prototype ARES device will be designed and tested on five health subjects. Software development will begin using data from 30 SA patients. The AP and the ARES can be used together or independently to offer accurate, inexpensive and easy to administer tests for the assessment and monitoring of SA. PROPOSED COMMERCIAL APPLICATIONS: An estimated 20 million people in the U.S. suffer from sleep apnea (SA), the majority undiagnosed. The Alertness Profiler and the Apnea Risk Evaluation System (ARES) offer accurate, inexpensive and easily administered procedures for the assessment and monitoring of SA and the measurement of daytime drowsiness. Both products will be marketed to industry, healthcare and epidemiologists. The ARES will also be sold directly to consumers. A searchable database describing SA prevalence, prognosis and outcome will be created with data generated from these products.